Published: February 19, 2005

Published: February 19, 2005

When a U.S. spy satellite first detected bursts of gamma radiation in 1967, analysts took the readings to be evidence of Soviet nuclear tests, which is what the satellite was looking for. Today’s astronomers know that gamma ray bursts come from outer space, not Asia. But back then the equipment wasn’t capable of pinpointing the source of the radiation, so suspicion was wrongly cast in the Russians’ direction.…

Published: February 19, 2005

When most people think of the invention of the wheel, the image that comes to mind is a caveman chipping away on a flat block of stone. Actually the earliest evidence comes from Sumeria in Mesopotamia around 3500 B.C., where a potter’s wheel is depicted on a clay tablet. About 300 years later a wheeled cart is depicted. The Egyptians of the Pyramid Age (2700-2200 B.C.) didn’t have the wheel. They used sledges (platforms on runners) to drag the great stones over the sand.…